It is known from practice that different types of machining of a workpiece, e.g., welding, cutting, engraving, heating or the like, can be carried out with a laser tool. The laser tools are moved in relation to the workpiece by means of multiaxial mechanical manipulators, e.g., compound tables, multiaxial articulated-arm robots or the like. During laser welding, the laser tool is usually guided by means of a pressing element in contact with and at a constant distance from the workpiece. Focusing optical systems with fixed and relatively short focal distances may be used here. Furthermore, laser remote welding, in which a laser with fixed and longer focal distance is guided by a multiaxial manipulator at a greater distance in relation to the workpiece, is known in practice. In addition, it is known in remote welding that the laser tool may be equipped with a scanning means, which deflects the laser beam and moves it in relation to the workpiece.
The process velocity of the laser beam at the workpiece, e.g., the velocity of welding, is limited in the above-mentioned laser machining operations. It is approx. 4-6 m/minute in case of YAG or CO2 lasers. Higher velocities of up to approx. 10 m/minute can be reached at present with fiber lasers or disk lasers. The velocity of displacement, with which the manipulator moves the laser tool along a predetermined path during machining, e.g., during laser welding, corresponds to the above-mentioned machining velocity. If machining operations are carried out stroke by stroke, e.g., during stitch seam welding, the manipulator can be moved faster during the transport phases between the welding operations. In most machining operations, e.g., laser welding, it is desirable to place as many weld seams as possible in the shortest possible time. However, these efforts are limited by the relatively low velocity of welding, especially because the manipulator must perform acceleration and deceleration operations with its axes during the transport phases and the velocity level is also limited hereby. Moreover, such acceleration and deceleration operations lead to higher mechanical loads on the manipulator.